RSV is a negative-sense, single-stranded RNA virus of the paramyxovirus family. RSV can cause severe respiratory infections in humans, particularly in infants and children, as well as in the elderly and immunocompromised. The RSV genome encodes the synthesis of several viral proteins, including three transmembrane glycoproteins (attachment glycoprotein (G), fusion protein (F), and small hydrophobic protein (SH)); matrix protein M; transcription antitermination protein (M2-1); regulatory protein (M2-2); three proteins associated with the nucleocapsid (N, P, and L); and two nonstructural proteins (NS1 and NS2). RSV strains may be separated into two main groups, genotypes A and B (RSV A and RSV B).
Human RSV (hRSV) is the major cause of severe respiratory infections such as bronchiolitis and lower tract illness affecting mostly newborns and young children. Approximately 30 million children younger than five years old suffer from acute lower respiratory infection due to hRSV, and hRSV causes numerous complications in premature born patients as well as infants suffering from congenital heart disease and immune deficiency. Long-term effects of RSV infection include central nervous system alterations, seizures, central apnea, and encephalopathy, to name a few. Over 200,000 deaths per year can be attributed to hRSV and there are no efficient therapies to counteract the disease. Therefore, efforts are focused on generating a vaccine to prevent hRSV infection as well as developing new therapeutic drugs to treat RSV infection and reduce the potential long-term effects caused by RSV infection.
In order for health care providers to determine the effectiveness of treatment for a particular individual or to determine the best course of treatment for a particular individual, it is important to determine the amount of RSV present in the individual and/or the genotype of RSV that has infected the individual. What is needed, therefore, are compositions and methods for the efficient genotyping of an RSV and for the efficient determination of viral load.